CN1195284A - Gels with antimicrobial physical activity for cosmetics - Google Patents

Abstract

A gel comprising 20% of the resulting product comprising at least one polyol, at least one (meth)acrylic polymer and at least one liquefying solvent of the general formula, R ₁ - O-(R ₂ -O-R ₂ ) _n -OR ₃ where R ₁ is hydrogen atom or C ₁ -C ₅ straight or branched chain alkyl, R ₂ is C ₁ -C ₅ straight or branched chain alkyl , R ₃ is a hydrogen atom or a C ₁ -C ₅ linear or branched alkyl group, and n is an integer ranging from 1 to 200,000.

Description

Gels with antimicrobial physical activity for cosmetics

The present invention relates to a gel with antimicrobial physical activity for cosmetic or dermatological use.

Most cosmetic or dermatological products suitable for topical application, regardless of their galenical form: oil-in-water emulsions, water-in-oil emulsions, lotions, lotions, gels, solutions, contain a or multiple antimicrobial substances. The reason is obvious: the raw materials used to prepare these products are rarely fully sterilized, and the resulting products (including fragrances, bioactive compounds, vitamins) are difficult to maintain in a sterile state. There is therefore a need to prevent contamination of the product with microorganisms which are detrimental to the health of the user or to the aesthetics of the product. During the production process (including the raw materials used), unsealed packaging, and especially contact with the environment or the user after opening and using will cause pollution.

In contrast to food or pharmaceuticals, cosmetics do not need to be labeled with an expiration date; they can and should therefore remain stable and in optimal condition (including their microbiological status) over the long term.

Chemical preservatives can be used in such products to achieve this protection. Various regulations in Europe, the Americas and Asia place strict restrictions on the choice of antimicrobial or fungicide molecules used.

To be effective, all preservatives should be chemically active, disrupting the cell walls or biochemical mechanisms of microbial cells, so it is no wonder that these microbicide molecules are sometimes damaging to human cells when in contact with them themselves. In fact, as the consumption of cosmetic and dermopharmaceuticals increases, the cases of intolerances (irritants, allergies) to these products grow in parallel. Studies by various dermatologists, pharmacologists or health authorities have shown that some accidents are caused by the preservatives contained in these products.

In addition, the ecological trends of our time emphasize that the cosmetic industry should offer "natural", "mild" or "low-irritant" products. People are looking for a way to protect creams without adding preservatives.

But formulating paraben-free cosmetics is not easy. At present, sterilized raw materials can be selected and produced under strict aseptic and hygienic conditions (laminar flow treatment in a sterilized container). However, there is still a risk of contamination during use. The above conditions can only be met by choosing special packaging that ensures that the appropriate dose is taken out each time it is used, and that prevents air and bacteria from entering the container.

Therefore, the kinds of preservative-free cosmetics that can be made are limited, especially the production, processing and packaging costs will increase significantly.

French patent 2682296 proposes a non-chemical antiseptic method, the main feature of which is the use of glycerol-based poly(meth)acrylate gel, which is characterized by a strong penetrating effect on the environment, so that the cosmetic preparations can be dehydrated by dehydration. inactivation of microorganisms. Microbial contamination test (for example, on a cream containing 40% of the gel in question without chemical preservatives, inoculate ¹⁰⁶ bacteria per gram of cream, control inoculation only in the presence of gel in the formulation 7 days) can illustrate the antimicrobial efficacy of the gel. The method described in this patent has proven to be practicable, but there are some disadvantages: the amount of gel required for the cosmetic composition is high (at least 40% in the best case; usually the proportion of this gel is 50%, even 60%). This limits the scope of use, and the formulator is limited by the structure and feel of the product. Another disadvantage stems from subsequent testing: it is difficult to prevent the resulting product from being contaminated by specific molds (e.g. Aspergillus niger), which requires little free water for growth and is therefore less sensitive to the dehydration effect of the gel .

The object of the present invention is to provide a gel which improves the preservative efficacy of cosmetics, in particular against the growth of molds, ie a gel which has improved permeability.

Another object of the present invention is to provide a gel with improved cosmetic properties, especially feel.

Another object of the present invention is to provide a gel with physical activity and antimicrobial efficacy, the proportion of which in the cosmetic composition is less than or equal to 20%.

The object of the present invention is a gel with antimicrobial physical activity that can be used in cosmetics or dermopharmaceuticals, comprising at least one polyol and at least one (meth)acrylic polymer, characterized in that it also contains at least one The liquefaction solvent shown in formula (1), and the proportion of gel in the obtained product is about 1-20%, R ₁ -O-(R ₂ -OR ₂ ) _n -OR ₃ (1) wherein R ₁ is a hydrogen atom Or C ₁ -C ₅ straight chain or branched chain alkyl, R ₂ is C ₁ -C ₅ straight chain or branched chain alkyl, R ₃ is a hydrogen atom or C ₁ -C ₅ straight chain or branched chain alkyl, n It is an integer of 1-200000.

Regarding other characteristics: - the general formula a, b, ... i ... -(alkyl)-poly-alcohol for each polyol wherein: ^* Alkyl is C _n linear or branched chain alkyl, n is 2-10. ^* Plity is the number of alcohol functional groups. ^* a, b, ...i represent different numbers from 1-10, corresponding to the substitution positions of the alcohol functional groups; - preferably R ₁ is C ₁ -C ₃ alkyl, and n is 1-3. - the proportion of liquefaction solvent in the gel is 5-50%, preferably 15-30%; - the polymer is derived from acrylic acid and/or methacrylic acid and is in the form of its salts, esters, amides; - the polymer in the gel The proportion of polyol is 0.05-5%, and preferably 0.2-1%; - the proportion of polyol in the gel is 1-99%, and preferably 30-70%; - polyol is composed of 30-50% glycerol and 2 - 8% composition of 1,2-octanediol. - The proportion of gel in the resulting product is preferably 5-20%.

Due to the physical antibacterial activity of the above-mentioned gel, the object of the present invention is also to use this gel for the preservative treatment of cosmetics or dermopharmaceuticals.

The invention is illustrated by the following non-limiting example of a gel of various components, which itself consists of a polyol, a poly(meth)acrylate polymer, a liquefaction solvent and water.

The general formula of polyols is: a, b, ... i...-(alkyl)-poly-alcohols, examples of which can be: -propylene glycol (a=1, b=2, n=3)-1,3 butanediol (a=1, b=3, n=4)-glycerol (a=1, b=2, c=3, n=3)-1,2-pentanediol (a=1, b=2, n =5)-1,2-octanediol (a=1, b=2, n=8)-1,8-octanediol (a=1, b=8, n=8)-mannitol or sorbitol Alcohol (a=1, b=2, c=3, d=4, e=5, f=6, n=6)-2-ethyl-1,3-hexanediol (a=1, b= 2, n=8, branched)

The polyol is preferably a mixture with a high content of glycerol. In a particularly preferred mixture, the proportion of glycerol in the gel is 30-50%, and the proportion of 1,2-octanediol in the gel is 2-8%.

Combining glycerin with other polyols improves the feel of the composition, formulatability, and increases the penetration of the gel, ie its ability to absorb free water, which also represents its antimicrobial efficacy.

The polymer is preferably selected from the sodium, potassium, triethylamine, triethanolamine, ammonium salts of acrylic acid and/or methacrylic acid, but can also be selected from the esters or amides of these acidic polymers, or from carbopol Formulation-type cross-linked derivatives - such as pentaerythritol, sucrose or allyl ethers of propylene cross-linked.

The proportion of polymer in the gel is 0.05-5%, preferably 0.2-1%.

The liquefaction solvent is preferably selected from ethers, such as methoxydiethylene glycol, ethoxydiethylene glycol (or diethylene glycol monoethyl ether), propoxydiethylene glycol, butoxydiethylene glycol, triethylene glycol monopropyl ether , or their esters, such as ethoxydiethylene glycol acetate, or ethoxyethyl acetate. The liquefaction solvent can also be selected from polyethylene glycol or polypropylene glycol, and the degree of polymerization can reach 200,000. These solvents are advantageously used in the form of a mixture.

An example of a gel according to the invention can be made from the following components: - 40% glycerin and 6% 1,2-octanediol, - 0.7% sodium polyacrylate, - 20% ethoxydiglycol.

The rest is water, or contains 33.3% water.

The proportion of the gel of the invention in the resulting product is 1-99%, but preferably 5-20%.

The gel of the present invention is applicable to various galenic preparations for cosmetics that require antimicrobial antiseptic treatment: oil-in-water emulsion, water-in-oil emulsion, emulsion, lotion, gel, cream, cleansing agent, etc. Hair lotion, shampoo, conditioner, soap, the list here is not limiting.

The gels of the present invention can also be used in combination with cosmetic compositions comprising other usual cosmetic ingredients: extracted or synthetic lipids, gel-forming and viscosity-increasing polymers, surfactants and emulsifiers , water-soluble or oil-soluble active ingredients, plant extracts, tissue extracts, marine biological extracts.

Cosmetic compositions comprising the gel of the invention can be used for conditioning or caring for the skin, hair, nails and scalp, i.e. for anti-aging, anti-wrinkle, anti-inflammatory, anti-acne, sun protection and anti-free radical, moisturizing and lubricating effects, anti-hair loss, prevention of Pollution and infringement treatment.

The gels of the present invention are particularly suitable for use in those cosmetic and dermopharmaceutical applications for sensitive, irritated skin, whereupon they are classified as "low irritation" or "mild" products, eg they have anti-irritant properties.

The efficacy of these gels is based on physical action (osmosis). The desired product is thereby formulated without chemical preservatives.

Claims (10)

1. A gel with antimicrobial physical activity for cosmetics or dermatology, comprising at least one polyhydric alcohol and at least one (meth)acrylic acid polymer, characterized in that it also contains at least one of the general formula (1) The liquefaction solvent shown, and the proportion of gel in the obtained product is about 1-20%, R ₁ -O-(R ₂ -OR ₂ ) _n -OR ₃ (1) where R ₁ is a hydrogen atom or C ₁ -C ₅ straight chain or branched chain alkyl, R ₂ is C ₁ -C ₅ straight chain or branched chain alkyl, R ₃ is a hydrogen atom or C ₁ -C ₅ straight chain or branched chain alkyl, n is 1-200000 integer. 2. The gel according to claim 1, characterized in that the general formula of the polyhydric alcohol is: a, b, ... i...-(alkyl)-poly-alcohol wherein: ^* alkyl is _C straight chain or branched chain alkane group, n is 2-10, ^* multiple is the number of alcohol functional groups, ^* a, b, ... i represent different numbers of 1-10, corresponding to the substitution position of alcohol functional groups. 3. Gel according to claim 1, characterized in that _R1 is _C1 - _C3 alkyl and n is 1-3. 4. Gel according to claim 1, characterized in that the proportion of liquefaction solvent in the gel is 5-50%, preferably 15-30%. 5. Gel according to claim 1, characterized in that the polymer is derived from acrylic acid and/or methacrylic acid and is in the form of salts, esters, amides of these acids. 6. Gel according to claim 1, characterized in that the proportion of polymer in the gel is 0.05-5%, and preferably 0.2-1%. 7. Gel according to claim 1, characterized in that the proportion of polyols in the gel is 1-99%, and preferably 30-70%. 8. Gel according to claim 6, characterized in that the polyol consists of 30-50% glycerol and 2-8% 1,2-octanediol. 9. The gel according to claim 1, characterized in that the proportion of gel in the obtained product is preferably 5-20%. 10. Use of the gel according to any one of claims 1 to 9 for the preservative treatment of cosmetic or dermopharmaceuticals on the basis of its physical antibacterial activity.